The present invention relates to an exhaust system for an internal combustion engine, in particular in a motor vehicle, and a respective operating method.
Such an exhaust system usually includes an exhaust line in which at least one oxidation catalytic converter is provided for treating the exhaust gases coming from the internal combustion engine.
When an internal combustion engine is turned off for a lengthy period of time, the engine and its components such as the exhaust system assume the ambient temperature. When the internal combustion engine that has cooled to this extent is started up, which is referred to as a cold start, there are increased emissions of pollutants due to the low temperatures prevailing inside the components involved. The oxidation catalyst has a definitely diminished oxidizing effect for unburned or incompletely burned hydrocarbons—or none at all—at temperatures below the operating temperature in particular. To comply with increasingly stringent environmental safety requirements, it is desirable to design the cold start phase of an internal combustion engine to be as short as possible.
The present invention addresses the problem of providing an improved embodiment or at least a different embodiment for an exhaust system and/or a respective operating method that will make it possible to shorten the cold start phase in particular.